There are a variety of conditions that require injection of fluids into, or withdrawing fluids from, parts of a body below the surface of the skin of the body. During the procedure, symptomatic gas embolism can occur when undissolved gas (e.g., air, CO2, etc.) accumulates in the heart and/or pulmonary arteries. This gas can compromise the circulation of blood through the lungs, causing serious injury or death. Health Devices May-June 1996; 25(5-6):214-5 reported a case of suspected gas embolism. During a hysteroscopy (performed with a patient under intravenous sedation), the patient gasped for air almost immediately upon uterine insufflation. Based on the clinical signs, the medical staff suspected that the patient's condition was caused by a CO2 embolism that originated in the uterus. However, a follow up investigation revealed that the embolized gas was probably air, not CO2. The air may have been introduced into the patient from the dead space in the tubing set used to connect the insufflator to the hysteroscope. This tubing set was not purged before insufflation began. Health Devices recommended that before delivering a fluid to a patient, one must purge air from tubing sets and instruments. Thus, there is a need for a valved catheter wherein the valved catheter comprises a safety valve having minimal dead space built-in the catheter tube that would automatically close to reduce the risk of blood loss or air embolism if an attachment to the catheter were to be inadvertently disconnected from the catheter tube.
A subcutaneously tunneled catheter is often selected when a catheter might be required to be implanted within a patient for weeks to months. A subcutaneously tunneled catheter can be implanted or removed in the outpatient setting and has a decreased incidence of infection. The typical procedure for implanting the tunneled catheter is by forward tunneling. However, another method of implanting the tunneled catheter is by reverse tunneling, as follows: (a) place the distal end of a catheter within a blood vessel through an entry site; (b) mark an exit location of a tunnel to be formed in a subcutaneous plane; (c) create a subcutaneous channel from the exit to entry site using a tunneler by pushing the tapered end of the tunneler through the skin; (d) attach the proximal end of the catheter to the tapered end of the tunneler; (e) pull the tunneler with the secured catheter from the entry to the exit site, through the subcutaneous channel, while gently holding the catheter distal to the cuff; and (f) detach the catheter from the tunneler and attach a bifurcation element thereto. During the described reverse tunneling technique, the proximal end of a typical catheter tube is open, permitting the entry of air. If the proximal end is clamped, the catheter cannot be reverse tunneled as described.
Therefore, there is a need for a catheter with integrated valve to provide protection at the proximal end of the catheter. In addition, for medical procedures requiring the implantation of a dual lumen catheter (e.g., hemodialysis catheter, etc.), it would be very difficult to tunnel the bifurcation connected to the proximal end of the catheter. Thus, it would be desirable to reverse tunnel the proximal portion of the dual lumen catheter prior to establishing a secure bifurcating connection with the dual lumen catheter.
It is also common to utilize a guidewire inserted in the vascular system to facilitate placement of a catheter, but its use can prevent capping the catheter to prevent fluid loss from or air entering the vascular system during placement. After catheter placement, it is common to attach a valved cap to the catheter connector(s) to prevent fluid loss from or air entering the catheter and vascular system. U.S. Pat. No. 6,575,960 (Bleed Back Control Assembly and Method) relates to a Y-valved connector. The ‘Y-connector’ includes a sealing valve that is normally closed except when accessed with a small diameter tube or wire. The sealing valve does not completely prevent air or fluid leakage, but relies on a second user compressible valve to provide a complete seal.
In short, there are several problems with the current valves. The flow path through the valve is restricted due to a restricted cross-sectional area, there is a dead space above or below the valve where blood accumulates, which makes it difficult to clean the valve, and the current valves are not designed for use with a guidewire traversing through the same valve. Also, the current valves cannot be accessed multiple times as they are typically screwed on to the catheter and discarded after use.
Therefore, there is a need for a valved catheter, which addresses shortcomings in the current products, reduces the risk of contamination, and permits repeated use thereof.